matthews at 5:00 person eastern leading up to the first presidential debate at 9:00 p.m. eastern time. >>> we are following breaking news out of arizona a border patrol agent has been shot and killed. >>> let me see here. that is a great question. i think justice scalia is a very good judge. justice kennedy. >> mass mistakes. fireworks during last night's showdown between elizabeth warren and scott brown. the stumbles, the highlights and who won the night? ♪ these are... [ male announcer ] marie callender's puts everything you've grown to love about sunday dinner into each of her pot pies. tender white meat chicken and vegetables in a crust made from scratch. marie callender's. it's time to savor. >>> welcome back. we are following this breaking news out of arizona. a border patrol agent has been shot and killed in naco along the border near tucson. both were patrolling on horseback in an area known as a drug-smuggling corridor. the wounded agent was air-lifted by helicopter to a hospital and is expected to recover. we'll work on more details and bring them to you. >>>